The invention relates to the field of lifting devices. In particular, this lifting device is used for lifting and lowering operations, for leveling purpose, for self-leveling and weighing of: aircrafts, such as aeroplanes, helicopters, civil and military aircrafts, watercraft, camping vehicles and similar, cars and trains, bridges, radar, and any other structure and/or object to which it can be applied.
Existing procedures for lifting of aeroplanes, helicopters, and civil and military aircrafts are used for weighing, balancing, maintenance and leveling, hydraulic jacks or self assisted for lifting, which are activated by manual methods. This manual operation is obtained by a minimum of five operators taking time of actuation. Moreover, there is a risk that a structural yielding of the hydraulic jack during the operation of lifting may cause damages to persons and things.
It is in fact obvious that the manual operation causes instability and lack of precision of the leveling, and consequently it is difficult to bring suitable corrections of the same weight, corrections that are required for the safety of the flight. Moreover, the operators move in a state of insecurity and dangerously, because they work under the same aircraft for the proper maneuvers, and they find difficulty in transporting the same hydraulic jacks for the attack upon the linking points of the aircraft; even uncontrolled movements of this aircraft are taken place during lifting and lowering operations, caused by suspensions of the main retractable undercarriages. This happens very frequently, and after many years of verifications in this field, these problems still remain caused to this empiric existing method of lifting. In the specific field of airlines and transport aeroplanes, civil and military, of transport and similar and however for aircrafts of big dimensions, for the operations of lifting, balance, leveling, maintenance and above all to centre the linking point of the aircraft, four hydraulic jacks or self assistant type are used, including a front one (secondary), two principal centrals, and an auxiliary rear which is controlled manually, during the lifting for the proper correction of the weight, because it must have respect of the maximum load allowed by the aircraft specifications of construction and to avoid damages to the structure and at the same time to control the exceeding weight. Moreover, dangerous lateral movements of the aircraft load with eventual structural damages of the aircraft can be verified during the operation of lifting and lowering caused to the instability of its linking point and of its load. The operators in order to avoid the disadvantage of lateral movements of the cargo of the aircraft, throw a mineral oil on the ground to make so that the movement of the axis of the linking point comes compensated from the forced sliding. This kind of operation is really difficult. Moreover it is imperfect to foresee more or less the exceeding load of the tail of the aircraft, which cannot exceed the established load of safety. In many cases structural damages of aircrafts have been verified.